I'm wondering if the 5.75" width is what the installer is reacting to. The width, for a nail in place, would indicate glue assist or full glue spread. As a floating floor, with EDGE gluing and transition strips at the required spots in the home, would not need the glue down/assist requirements.

You have carefully researched your product. You have asked and reasked the same questions to ensure you understand the process. You have done everything possible to be well informed. You have specifically stated you WANT a floating floor. The installation instructions (https://pantimhardwoodflooring.com/wp-content/uploads/2018/12/instruction.3-ply_English-604.19-1.pdf) CLEARLY state the PanTim can be floated (it even has the instructions for in-floor radiant heat and the floating method).

You have handed your installer the perfect product for your situation. You are not asking for him to reinvent the wheel. He does not need to relearn his trade. You are not asking to have a floor do something it is not designed to do. He simply has to install the floor in the way you have wish.

Because he's been so patient, you might as well ask him WHY he firmly recommends a glue down install. I'm going to bet my first born (he's pretty cute so I don't do this lightly;-) that the installer has been BURNED by a floating install in the past. I'm guessing he installed a floor that brought SOOOO much grief (because of the bounce, the click or the hollow sound) that he has sworn he won't do it again.

If he's as good as you feel he is (your so well informed that I doubt you would hire a hack) he has probably 'forgotten' about your conversations in the past. I would remind him that you have done everything to achieve a great floating install (yes you know about the bit of bounce/give and you are looking forward to it!!). You are interested as to why he is so opposed to the floating install with a product specifically designed AND chosen for a floating install.

Hi Mittens.

At the outset I will say that I would never lay an engineered timber floor glued direct to concrete.

There are a few reasons for my point of view and although many people do glue it, I don't and below is why....

Laying any timber flooring over a concrete floor requires a couple of issues to be dealt with regardless of method. They are; how level is the floor and what is the moisture content/treatment of the concrete (as it affects movement)?

When concrete is laid and it cures, there are often high and low areas/points that are not evident without a long straight edge. Floating timber floors are susceptible to these dips which can create an air pocket and 'clacking' noise in addition to excessive flexing at the join over time.

In your case, and for that reason, the product has a maximum tolerance of 3/16" over 10', meaning that the floor cannot deviate from level outside of that amount (we usually work to 1/8" over that distance).

If it does deviate, a self leveling concrete will need to be applied in the low spots. Some installers get around this by using a pressure sensitive adhesive that they 'bulk up' in the low points to save on work. Either way, I would be asking your installer how he intends to address the level of the floor.

Regarding moisture, there are two differently operating materials here. Concrete expands and contracts with temperature whereas timber reacts to moisture, and then only in relation to the grain (linear expansion). This is why the engineered floors have 3 layers at right angles to the other layer ie it helps to control the expansion. If you glue the engineered floor direct to the concrete, you are subjecting it to the differing movement of the concrete, and also providing a bridge for moisture within the concrete to move into the flooring.

It is critical that you check the moisture content of your slab if you are going to glue it down, and have your installer detail how he is going to address moisture proofing the slab. It must not be greater than 12% or more than 4% different than the timber floor itself.

When we install solid timber floors over concrete, we level the floor, apply a waterproofing membrane, then glue and nail plywood down before also gluing and nailing the solid timber. If we are installing floating then we again moisture proof and level the floor before ensuring that the underlay is installed at least an inch up the wall.

The manufacturer of your product is silent on whether the product can be glued down on a concrete floor. The sub floor types detail gluing over vinyl, plywood/OSB and terrazzo but not concrete.

If you feel that you have to have it glued then I would be contacting the manufacturer and confirming that this method is warrant-able.

Again, I would be asking your installer about how he intends to address slab moisture. Other than that I would certainly be asking the installer why he wants to glue it beyond easier installation.

Cheers

Your flooring contractor does not have the equipment or know how to prep a concrete subfloor properly. As two's company reno mentioned. They can cheat by bulking up the glue in the low spots. The problem is that it also, causes adhesive to come through the joint. Rolling and foot traffic will cause excess glue to squeeze up through the joints. Making it a nightmare for clean-up.

New concrete slabs need to cure for minimum of 30 days before you can do any type of flooring installation over it. If, any wet work is done over it. The slab needs to be re-cured. If, there is heating and cooling in that space. The system needs to run for 30 days to re-cure the slab.

"He simply has to install the floor in the way you have wish."

That's "how" in my book and my customers never get it.

They get where, when, why, and what, but how and who are always mine. Nonnegotiable.

IMO ask a few more questions about why We have few concrete flors in homes where I live so don’t often have this issue except in basements but to me a glue down on concrete with wood floor is asking for trouble with moisture for sure but I would want to know why. Also as mentioned the floor itself needs to be perfect.

The floor HAS to be flat for either method. That prep work is non negotiable. It’s also extra $$$.

Glue down to a flat subfloor is the much preferred method. It’s quieter and gives the same feeling as solid plank. Floating is noisy. It’s for laminate and other faux wood floors.

Thank him for his advice, inform him of your preference (again) and ask if there's any issue with the levelness of the subfloor causing any issues. I regularly warn people about potential issues with floating floor, but more regarding the greater noise they generate, even with the most effective underlayment. At a certain pricing/home value level, customers more frequently object to the noise, though floating does reduce the amount of chemicals used and provides a more forgiving floor to walk and stand on.

Thanks all! I didn't want to overwhelm with too many details, but here's Flooring Guy's rationale for glue (he suggests Sika):

"Glue is more resistant to everything and if in the future some moisture enters your floor, it will not be damaged by the glue. If we float it, the floor is very delicate and if we use glue it is going to be much stronger." He added he felt that we'd be bothered by potential creaks if it was floated, and over time, all the movement will accelerate the wear and tear (on the tongue and groove and base layer) and we'll end up having to replace it sooner.

(BTW, I am paying directly for all materials, so it's not like he's getting a commission on glue.)

More info, if it helps:

Floor Guy (FG) was already prepping the older portion of the slab yesterday when I arrived. He was using some sort of large grinding tool and had a couple long levels. He definitely seemed to know what he was doing, but what do I know (touche to @Joseph Corlett, LLC on that point!).

FG laid the level down and tried to point out some issues, but they were pretty much lost on me. I knew he was going to have to redo the area at the front entry, as for some reason there was a patch of old decrepit plywood there--and only there--atop the slab.

He'd been to the house 2-3 times before (months ago, we paid him $1,000 to carefully pull up the old Junckers hardwood that had been nicely floating for 20 years--we'd planned to save and reuse the Junckers at that point). So, it's not like he was just discovering the condition of the slab for the first time.

Up until a couple month or so ago, we were pretty sure we were going with Junckers or Kahrs, which feature clip and "wood lock" systems respectively, adding to their stability when floated. But then I turned my sights on other engineered hardwood, making sure I was considering those whose warranties said they could be floated. I had occasionally updated FG on my epic floor shopping and (looking back on texts now) I can see I mentioned a couple times that we definitely wanted to float the floors. But I also see he pointed out that "more concrete work" would be needed if we glued it down.

FWIW, around here (SoCal) it seems most flooring people see glue down on slab to be the way to go. I've had a few people look at me oddly when I mention floating. One said, "Why would you do THAT?" I think everyone has a bad memory of early bouncy Pergo? But like I said, I loved the feel of the SLIGHT give we had with our Junckers...though Flooring Guy and our GC pointed out it was probably due to the Junckers being a SOLID floor, not engineered. (Thoughts on that anyone?)

Our GC briefly entered the conversation yesterday, but being someone who wants everything done as solidly as possible (and not being super clued in about chemical sensitivities--an issue in our home), he obviously thought I should go with FG's recommendation but left us to work it out.

FG requested an additional $500 for prep work on the slab. I agreed without hesitation.

The conundrum in a nutshell: do I go with my untrained gut and insist on floating, or do I go with a professional's recommendation (bias?) and risk problems?

Bottom line: we didn't want glue all over the house, which is why I chose (and paid a bit more for) an ECO-approved engineered floor that can be floated.

Thanks all. I wish I could send you all early Halloween candy for your trouble! :)

@SJ McCarthy, sorry I missed this bit: I didn't realize the specs say 5.75" planks. I just had FG check and he sent me a pic showing they are over 7" wide. Hmm! Maybe the specs are wrong (geez).

UPDATE: I just checked and the PanTim person and it turns out our floor is from their Palladio Collection, which is the wider (7.5") version of the Genuine French Oak line. (Also, my "Pilsner" color = "Whiskey" in the Palladio collection.) Otherwise everything should be the same. Here are the instructions.

Oh, and I should also mention I know we have to glue the edges of the planks, so there's plenty of glue there with that. (The manufacturer recommended Dri Tac when I inquired.)

I would follow the instructions that doesn't void my materials warranty.

I'd be afraid of cupping if it's glued down.

@BeverlyFLADeziner, thanks. Instructions state it can be glued or floated.

If it isn't painfully obviously, I'm a stickler for details...at least in regard to following instructions exactly to protect a substantial investment! :)

My concern is trapping moisture from the slab. I've seen this happen before, but the plank wasn't this wide.

@BeverlyFLADeziner, just so I am sure, you mean there's a concern that glue would trap moisture in a slab? I didn't realize this was a possibility (though we are in coastal SoCal, much less humid than your Florida, I presume!).

Now wondering if there are glues that "breathe" better than others? But I'll stick with whatever materials the manufacturer recommends, obviously!

FWIW, the flooring distributor who sold us the floors (and knows about our chemically sensitive family members) had this suggestion for glue, if we go that route: Bostik GreenForce

He also said none of their installers prefers floating over gluing, but he didn't elaborate as to why. One possible clue: the Bostik info states, "GreenForce® hardwood flooring adhesive has extremely low moisture vapor permeability and is not adversely affected by moisture. As a result, costly and time consuming concrete moisture testing is not required when the slab is properly prepared, dry to the touch and fully cured."

Alas, for our job, glue will add up to another $2,300 (double the cost of underlayment). Sigh!

Just had engineered European white oak floors laid on concrete slab in humid area. The slab was leveled and the floors were glued. The glue used is moisture resistant and has some type of rubber in it for give. Floors in last house done same way with no problems over the years. They were also comfortable to stand and walk on. Our floors could have been floated also but glue was the installation preference and also installer's recommendation.

Thanks. I just spoke with a local certified installer from the National Wood Flooring Assn and he said he floats all own his floors, but around our area glue down has become the norm.

Also, my installer just admitted he has only floated a couple of floors before (I wish he'd mentioned this months ago!). Nice guy, but now I feel I should be interviewing other installers, asap.

My flooring guy was also not in favor of floating. I would definitely talk to someone else who had experience with floating to be safe.

Glued sounds so much better than the tap tap tap hollow floating stuff.

GreenGlue is awesome stuff. And a much better moisture barrier than taped polyethylene. It’s FLOATING floors that have moisture and mold under them, not glued down with the right glue. The taped plastic vapor barriers of floating allow the water to pass right through the concrete and condense under that vapor barrier. You pull a floating floor up in Louisiana or Florida, it will be wet and moldy under it.

With the right waterproof glue, like Green Guard, or the addition of a roll on moisture barrier to a standard moisture resistant polyurethane glue, you can completely prevent any water from migrating through your slab. Cupping occurs quite often with floating wide plank, as the ONLY method of keeping that from happening is a standard full spread glue down with the correct permeability rating for the moisture readings taken of the slab. Planks that side that are nailed are required to also be glued. For a reason.

@User, are you referring to the Green Glue that is used for sound deadening? Or GreenForce from Bostik? Or?

When we installed engineered wood in our previous house, the floors were leveled and a moisture barrier was applied, then glued down. No isses,issues, no creaking etc,

I just spoke to another longtime installer (referred to me by a hardwood flooring inspector) who, though very friendly and generous with his time, just scared the living bejeebers out of me! His final conclusions were basically no matter which method we choose, there is no getting past the many, many, many strict guidelines that various companies (flooring, glue, underlayment, et al) require installers to follow to the T, otherwise the warranty is kaput. He also told me the store I bought my flooring from has a reputation for not backing up customers who make claims. What fun.

And my DH wonders why I don't sleep at night.

I don't have advice, but this is my experience:

I am in coastal So Cal. My dad and I installed floating engineered hardwood on a concrete slab throughout the ground floor about 15 years ago. It has held up well. About 10 years ago we had an upstairs leak that required replacement of the downstairs floor in one room. Contractors glued it down and it has buckled. I am assuming that was because they didn't leave room for expansion rather than a problem with moisture from the slab.

Hi Mittens

The statements from your FG that floating floors are delicate, floating accelerates wear and tear on T+G and gluing down an engineered floor because it is wide reveal his inexperience.

We've installed a 7.5" wide engineered floating floor over a brand new concrete sub floor in my own home in a large living area, kitchen, hallways, entry over 20 years ago and it's still going strong without sanding, warping, cupping or any issues whatsoever.... (and it has survived some epic birthday parties over the years).

It doesn't matter what floor you install, the same issues need to be addressed , moisture and floor level. Do it right and you eliminate the problems. Then obviously comes the method and competency of the installer.

When it comes to installation of a floating floor, there are installers, and there are installers.

Your installer needs to ensure that there are sufficient expansion gaps all around the floor perimeter, regardless of the method of installation. This takes a bit of work and technique that not all customers are prepared to pay for until they understand the reasons and the benefits.

For example, it is critical that you don't bind the floor and eliminate the expansion points because it is easier for the installer in tight areas. If you install a floating floor, it must be able to float. If you don't then you obviously void the warranties.

We've seen so many installations where the floor is cut neat around a door frame and then gaps are caulked with a timber putty (this binds the floor...) instead of undercutting, or hard up against a kitchen bench instead of fitting the kicks afterward, or waterfall ends landing on the floor, or base boards binding the floor because no (eg laminate sample) spacers are used.

Regarding moisture, the installer will need to apply several layers of a paint on moisture proof membrane. It does not allow moisture through. We then use a moisture proof underlay as added insurance. There are no mould or damp issues unless someone hasn't done the proper job.

Regarding repairs through moisture, a long standing repeat client of ours recently suffered a major leak onto their floating floor (that we did not lay). The advantage of the floating floor is that we've stripped it for them, simply pulled up the underlay and allowed it all to dry out and are now supervising the replacement of planks in the affected area. No sanding, no issues.

Lay it right and you will have many years of trouble free use.

I can not stress enough those who have mentioned warranty. If you don’t follow the manufacturers methods to a T you risk it all.

If the product says it can be floated and you have stated the desire to limit glue use in your home then it’s worth the time to find the right installer. Just a side note - the latest carpet technology is using a soft back method (no latex use). Just FYI in case you have any rooms with carpeting.

Thanks for all the input. But geez, I think I'm ready to give up on hardwood and polish our concrete slab at this point!

I think back 20+ years ago to when I did months of research before choosing a Junckers solid hardwood floor (which was floated) and other than a couple of tiny gaps, we had zero problems. The installer at the time was not very experienced and probably took lots of shortcuts, but it came out fine. (I realize Junckers' clip system for floating is probably easier.)

I told my installer this morning to go ahead and go with glue (albeit as green as possible) since that's what he's more comfortable with. I decided to heed @Joseph Corlett, LLC's words earlier in this thread and let the installer go with what he thinks best. We live with windows open much of the year, so hopefully that'll make up for any gassing from the glue (with apologies to the atmosphere!).

You might want to ask your question over at the wood flooring forum. I feel that much of the advice you're getting here, however well-meaning, isn't all coming from those as considered and knowledgeable as Two's Company.

It seems to me like your installer is knowledgeable and considerate, and he and your GC are careful and attentive, and I would trust them - it's on them if things go pear-shaped, after all.

I'm wading through the same considerations myself, albeit in a very different climate - major swings in heat and humidity here, plus we've got radiant in-floor 4" beneath the concrete slab.

Best of luck!

@bubblyjock, thanks I'm wading through that wood flooring forum now. I actually forwarded @User' comments to my installer to give him the heads up. Fortunately he is very humble and seems to appreciate all the input and advice...or he's a great actor! :) Looks like we are going with Bostik GreenForce, fingers crossed! (I was happy to hear my installer say he's bought a new trowell that meets Bostik's strict requirements.)

One thing I just saw on that forum that sounded good to me: bring in an outside (objective) inspector from the NWFA for a pre-installation consult. I spoke to one last night and wish I could convince him to pay a visit but he was so booked up. He was very generous with his advice, though (I forwarded that to my installer as well).

One of these days I will go back to my ol' normal life, right? :)

To put the cap on this thread, we ended up going with Bostik's GreenForce for glue down. Fingers crossed, but so far I really love this floor---enough that I just ordered more SF to cover a small office, powder room and family room (all of which I had planned to cover with a cheaper material). Thanks everyone for the input!

Beautiful floors! I think you'll be pleased with your decision to glue.

@HU-161159613, thanks. I hope so. I've been aiming hard at being as green as possible (for my kid's chemical sensitivities as well as resale perks in our Lorax-loving town), so it was hard to give in to glue, even if it was no VOC Bostik Green Force.

looks great

Very nice! This has been a great thread, thanks for wrapping up. We're going with a similar-looking white oak, engineered, wide-plank, from Lauzon, so it's always good to see a similar installation.

@bubblyjock, Lauzon was on my short list! I just couldn't get a color to match up well with my yellowish walnut kitchen cabinets. Good luck!

Update, after living with the floors for 2 weeks. Love the floors, but NOT the rock-hard, cold feel of the glue-down installation (over concrete slab). Really bummed I didn't push back and insist on floating these beauties. I've had to change from my lifelong barefoot lifestyle to wearing comfy shoes and slippers in the house. Oh well!

Oh MIttens! I've been rooting for you! I'm glad you love the floors. I'm sad you have to deal with the cold that seeps up from the slab. I wish, wish, wish you didn't have to go through this. Sigh.

But you are safe, your family is safe and the New Year is upon us. I wish you and your peeps all the best.

BTW: You can have some SERIOUS fun with house socks. In Canada we make a MEAL of house socks. We give them. We buy them for ourselves. We force family members to wear them. We have competitions to see who can find/purchase/wear the MOST OUTRAGEOUS house socks ever! The best to date: 300 lbs manly-man firefighter wearing "big foot" slippers! Ha! Gotta love family!

If that's not your style, then a STUNNING pair of hand made moccasins (the dear leather is beautiful but delicate; I recommend moose hide - they will outlast you and your home!) would make a great addition to your home.

And if you are a barefoot type of gal, a nice pair of 'flip-flops' made by sketchers, etc with a beautiful thick sole might do it.

@SJ McCarthy, thanks! We are SoCal beach folk here, so shoes always feel a bit of imposition! But I dug out a 15-year old pair of barely-used Uggs and also snatched a pair of microfiber mop slippers from HomeGoods! :-)

I'm not really a big fan of rugs, but I guess it's time to give in to that expense as well. At the moment, we have a dozen IKEA mats and runners offering a bit of respite. Yoga mats, too! :)

And YES!!! I absolutely do not forget we are safe and warm and well-sheltered, every day!!! So very lucky to have been able to do this remodel, despite the petty gripes!

" Love the floors, but NOT the rock-hard, cold feel of the glue-down installation (over concrete slab). Really bummed I didn't push back and insist on floating these beauties."

Sorry, but in this contractor's book glue-down is "how" and I never give my customers "how". I'd give them their money back if I felt any push. No hard feelings.

@Joseph Corlett, LLC, I appreciate that, but this contractor and I met at the remodel site 3-4 times over the past 9 months and each time I talked about my strong desire for a floating installation and he never disagreed. We discussed a variety of underlayment material, etc. and he was in the loop as I was shopped for good quality floors that could be floated. It wasn't until a week or two before installation that he suddenly brought up glue down.

How are your floors holding up? I like the Pallido in Lager but there are some bad reviews out there. We live in Los Angeles so probably similar climate.

Thanks!!
Lynn

... and on we go but that's ok ... some time we'll replace all the wall-to-wall. I wonder with glue down- what happens way in future when it would be removed...?

Hi @Lynn Morford, I hate to jinx things, but now three months in, I LOVE the floors. I fact, I admire them many times a day (good distraction from current CV craziness). There are about a dozen spots where there were dings or tiny cracks, which freaked me out at first, but I'm pretty sure it was just from the movers. I do take care of them like a newborn child, though--sweep, vacuum, wipe, repeat. Overall, I'm very happy with them!

@everdebz, we ended up gluing down. Definitely harder on my body that floating but I've learned to wear slippers or socks and I have yoga mats in most rooms to give my feet a little vacation as I walk through the house, lol. In the end, I trusted @Joseph Corlett, LLC's comment about letting the contractor make the call on what is best for the situation. Granted, I still pine for the perfect floating feel of my old Junckers flooring, but apparently theirs were unique and most other flooring can't float the same way, so... Anyway, the sad fact is, you can't remove glue-downs without destroying the boards. So fingers crossed you never have to! (I put fake wood in my laundry room and we've already had three floods, so thank god for that decision.)

@mittenscat Thanks for getting back to me! I just ordered them today in lager! Fingers crossed they hold up well but my floor guy said the distributor here (Virginia Hardwoods) is great about claims if something does happen.

@Lynn Morford, congrats! Virginia Hardwoods (in SoCal) was also our regional distributor (I bought from one of their wholesalers 50 miles away), so good to hear that! I pretty much pestered everyone from the PanTim top people down to everyone through the supply chain to make sure I was making the right choice. I just used my dreamy Dyson Animal Stick (SO GREAT) to give the floors another cleaning. Cheers! p.s. this is the first time I've visited houzz in months (nice distraction), so hopefully next time I visit I will see your finished install! :)

@mittens cat We were told today that Virginia Hardwoods is shutting down for two weeks so we wanted to get our order in fast. It’s such a hard time to be finishing a house ... everything is changing and uncertain. Take care!

We had our floors glued down on concrete. Moisture was checked and Floor was leveled where needed. It’s been a few years and both look new.

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@Lynn Morford can't wait to see your finished floors. :) And re those negative reviews, let's hope that was just an extremely small percentage. One thing that I think all reviews should mention: whether there are dogs in the home and whether people wear shoes. We are a one cat, shoes off household here, so I expect that increases the odds against problems.